Dynamic Analysis of Multiply Tuned and Arbitrarily Supported Secondary Systems

摘要

The objective of this study is to include all of the important and complicated dynamic characteristics in a dynamic analysis of linear, multi-degree-of-freedom (MDOF) secondary subsystems with multiple support points attached to linear MODF primary subsystems. These characteristics include: interaction between the two subsystems; cross-correlations between motions of the support points and modal responses for stochastic input; resonance or tuning phenomena when a set of frequencies of one system is tuned with one or more frequencies of the other system; and non-classical damping effects when the damping ratio of the two subsystems are different. The basic approach of the analysis is to consider the combined primary and secondary subsystems as a single dynamic assemblage. Such an approach implicitly includes the effects of interaction, multiple support motions, resonance, and non-classical damping, but was avoided in the past due to the size and complexity of the resulting eigenvalue problem and the fact that such systems are non-classically damped. The main results of the analysis are applied to several representative example systems and compared with results obtained from numerical analysis.